With the recent increase of open source software (OSS) programs, some developers do not implement each functionality required for software development. Instead, they increasingly perform code cloning which means copying or reusing some or all of a code implemented in well-known open source software. Such code cloning has advantages in terms of reduction in development time and costs. Therefore, recently, many developers have used code cloning in well-known open source software when developing software.
However, code cloning may violate an open source license due to code copying which does not comply with the license policy. Also, if a bug or security defect is present in original software, the bug or security defect can also be copied by code cloning. Therefore, the same bug or security defect of the original software may also be present in code-cloned software.
In this regard, Korean Patent Laid-open Publication No. 10-2014-0001951 (entitled “Intelligent code differencing using code clone detection”) discloses a technology of identifying a large and complex source code change and tracking the change using a code differencing tool.